Reinforcement of Waterborne Polyurethane Films with Poly(acrylic acid)-Modified Palygorskite Fibers

Palygorskite (PAL) is a natural fibrous clay mineral which attracted tremendous attention as reinforcing agent to polymers. In this paper, a facile and environmental friendly modification process of PAL by poly acrylic acid (PAA) via in-situ polymerization in PAL/water gel has been reported. The effects of PAA modified PAL (PAA-PAL) on the mechanical and thermal properties of waterborne polyurethane (WPU) nanocomposites have been investigated. Scanning electron microscopy (SEM) demonstrated that the dispersion of PAL has improved dramatically after PAA modification. Tensile tests showed that PAA-PAL has a significant reinforcement effect on WPU matrix. Addition of 10 wt% PAA-PAL, the tensile strength and the Young’s modulus of WPU composites increased 235 % and 388 %, respectively. Furthermore, the thermal stability of WPU also has been distinctly improved via addition of PAA-PAL.